MEMS have many applications including micro optical components, such as Fresnel lenses, optical gratings and corner cube reflectors. The structures are usually fabricated on a silicon substrate. Using sacrificial layers and other techniques, a MEMS includes at least one flap which rests on the substrate. The flap is hinged on one side, and when actuated, rotates off plane around the hinge and off of the substrate.
The flap can be raised from the substrate using magnetic actuation. However, off plane displacement of the structure requires a constant source of energy, which is usually provided by a dedicated on-chip micro actuator that is mechanically, electrically or magnetically linked to the flap. The ability to deploy large arrays of devices is compromised because each actuator must be individually biased. Moreover, most actuators occupy a relatively large chip area (on the order of 100 .mu.m.sup.2) in addition to the flap itself, which increases die sizes and limits the ultimate area density of integrated optical MEMS.
Thus, there is a need for MEMS processes and designs which do not require a constant source of energy to be maintained in an off-plane condition. There is also a need for MEMS processes and designs which do not require individual biasing, and do not require a relatively large chip area, if desired.
Accordingly, one object of the present invention is to provide new and improved MEMS using magnetic actuation.
Another object is to provide new and improved MEMS which do not require individual biasing apparatus.
Still another object is to provide new and improved MEMS which do not require an actuator on an integrated circuit on which the MEMS is assembled.
Yet another object is to provide a new and improved MEMS having multiple flaps which are asynchronously actuated by a single magnetic source.
A still further object is to provide a new and improved MEMS having multiple flaps which interlock when assembled to form a three dimensional structure, and do not require a constant energy source to remain assembled.